Wednesday, November 7, 2012

Understanding Climate Change - Glossary

This is the glossary for readings 1-7 for my course on climate change.

Understanding Climate Change - Glossary

(Alan Holyoak, PhD)

Absolute path
(Coriolis effect) – The path of a moving object actually moves in a straight
line even though the Earth is rotating under it.

Absolute reference frame (Coriolis effect) – The observer is stationary in
space and the path of a moving object is in a straight line with the Earth
rotating under it.

Absolute zero
– This is zero degrees Kelvin (-273oC or -459oF), and
indicates the complete absence of heat, i.e., when molecules stop vibrating.

Absorption –
In terms of electromagnetic radiation, this occurs when photons of energy are
taken up by matter.When a photon is
taken up, an electron becomes energized and moves to a higher energy state.Energy is released when the energized
electron releases the energy it absorbed and it then drops to a lower energy
state.

Abyssal plain
– A flat plain that makes up the majority of world’s seafloor 3-6 miles below
the ocean surface.

Abyssalpelagic zone – Ocean depths from the 4oC depth mark to 6000 meters, and
reaches all the way down to the abyssal plain.

Aerosols –
Particulate matter and droplets of liquid small enough to remain suspended in
the air for an extended period of time.

Albedo – The
reflectivity of a surface as measured on a scale of 1.0 to 0.0.A perfect white surface will reflect all
radiation that strikes it and have a value of 1.0, while a perfect black
surface will absorb all radiation that strikes it and have a value of 0.0.

Anoxic – A
situation where there is no oxygen present.

Antarctic Circle – Line of latitude at 66.5oS that experiences one day each
year where the sun does not rise above the horizon (that’s on the northern
hemisphere summer solstice).

Anthropogenic
– Produced or generated by humans.

Apparent path
(Coriolis effect) – The path of an object moving over the Earth appears to
deflect to the right in the northern hemisphere and to the left in the southern
hemisphere, but only if the observer is on the surface of the rotating planet.

Arctic Circle
– Line of latitude at 66.5oN that experiences one day each year
where the sun does not rise above the horizon (that’s on the northern
hemisphere winter solstice).

Autumnal equinox – The day between the northern hemisphere summer and fall when
everywhere on the planet has equal day and night lengths, usually around Sept
22nd.

Bathypelagic zone – This layer in the ocean exists between the 10oC and the 4oC
temperature layers.This layer is in
perpetual darkness.

The Big Experiment – The experiment involves the emission of increasing amounts of fossil
carbon into the atmosphere, starting during the Industrial Revolution, that
affects the amount of greenhouse gases there and the atmosphere’s greenhouse
efficiency.

The Boring Billion Years – The time period between about 1.8 – 0.8 billion
years ago when the amount of oxygen in the atmosphere stayed at constant, low
concentrations.

Calcium carbonate – A white compound made of one atom of calcium (Ca) and one carbonate
ion (CO3-2).This
compound is extremely common, and can be made by organisms such as coral,
snails, foraminiferans, etc.

Carbon cycle
– The dynamic action of chemical, biological, and geological processes that
release, take up, and store carbon on our planet.

Carbon sink
– Any process that removes carbon from the biosphere.

Carbon source
– Any process that releases carbon into the biosphere.

Coal –
Fossil fuel that was formed when ancient forests died, presumably in swamps,
were covered by sedimentary rock, and under intense temperature and pressure
became coal.Coal contains carbon,
hydrogen, and impurities like sulfur.

Continental shelf – Seafloor with a shallow slope that extends from the edge of a
continent to the continental slope.

Continental slope – Seafloor that has a steep slope and drops from the outer edge of the
continental shelf to the ocean’s abyssal plain.

Coral –
Coral are animals related to sea anemones and jellyfish.Some corals secrete calcium carbonate
skeletons that form the framework for coral reefs.

Coriolis effect
– The apparent deflection of a moving object that is not attached to the earth,
e.g., wind or water currents.Coriolis
effect causes moving objects to deflect to the right in the northern hemisphere
and to the left in the southern hemisphere.

Cyanobacteria
– Also known as blue-green algae or blue-green bacteria.These bacteria carry out photosynthesis, and
are believed to be the first group of photosynthetic organisms that appeared on
Earth.

Deep-water currents – Ocean currents below the thermocline, existing all the way to the
seafloor.Thermohaline circulation forms
and drives these currents.

Diffuse radiation – Scattered light that reaches the Earth’s surface.

Direct solar radiation – Solar radiation that passes through the atmosphere
to the Earth’s surface without being scattered, absorbed, or reflected.

Eccentricity
– Milankovitch cycle describing the oscillations of the shape of Earth’s orbit
around the sun.

Ekman spiral
–Surface waters move due to friction between it and surface winds.The next layer of water down also moves, but
due to Coriolis effect it moves in slightly different direction, and so on for
each succeeding layer of deeper water.This produces water moving in different directions at different depths.

Ekman transport – Surface waters move due to friction with surface winds.Where Coriolis effect surface water to move
away from the shore, deeper water is pulled to the surface, upwelling.

Electromagnetic spectrum of radiation – The range of all wavelengths of radiation from
gamma rays at the shortest wavelength to long radio waves at the long end.

Energy budget
– This is the balance between the amount and rate of energy entering a system
and the amount and rate of energy leaving a system during a period of time.

Entropy – Entropy
is used to indicate the efficiency of energy transformation.The amount of energy available to do work
before energy transformation equals the amount of energy able to do work after
the energy transformation plus entropy.Or, entropy represents waste heat no longer able to do work whenever
energy transformation takes place.The
amount of entropy in a closed system increases or stays the same.

Epipelagic zone
– This the top layer of the water column in the world’s oceans, and it extends
from the surface to a depth where only about 1% of the light that strikes the
surface has not been absorbed or scattered.This is usually the top few hundred meters of the ocean, and is where photosynthesis
occurs in the ocean.

Equinox –
Two days each year when the length of day and night are exactly the same
everywhere on earth: Vernal (spring) equinox and Autumnal (fall) equinox.

Ferrel Cell
– Air circulation pattern where air rises at 60oN & S and returns to the
surface at 30oN & S.This
produces low pressure and higher amounts of rainfall at 60o, and
high pressure and low precipitation at 30o.

First law of thermodynamics – The total amount of energy in closed system will
remain constant.And energy (i.e., heat)
will move from a location of high energy to low energy until the amount of
energy is uniform throughout the closed system.

Foraminifera
– One of the most abundant groups of marine plankton.They are related to amoeba, and they secrete
a calcium carbonate (CaCO3) shell.

Fossil carbon
– Carbon that was once part of a living thing, but has been removed from the
biosphere, embedded in the sediment and formed coal, oil, or natural gas.

Fossil fuel
– Once living material, mainly algae, plankton, and trees, that become
fossilized into coal, crude oil, and natural gas.

Freezing point depression – Water has to get colder to freeze when it contains
lots of salt (solutes) compared to when it contains less salt (solutes).

Gigaton – 1015
grams (= 1000 trillion grams)

Global conveyor
(a.k.a. Atlantic conveyor, conveyor belt) – Deep-ocean current established and
driven by thermohaline circulation.Water takes 100s-1000s of years to finish one complete cycle.

Global Warming Potential (GWP) – A measure of the ability of a single molecule
of a substance to absorb infrared radiation.Carbon dioxide is assigned a GWP of 1.0, and the GWP of all other greenhouse
gases are based on the CO2 standard.

Great Oxygenation Event – Time period between about 2.5 – 1.8 billion years
ago when oxygen first accumulated in Earth’s atmosphere.

Greenhouse effect – Infrared radiation is released by the Earth’s surface and by
molecules in the atmosphere.That heat
is absorbed by greenhouse gases in the atmosphere that then release the energy
in random directions.This slows the
rate of heat loss back into space.

Greenhouse gas
– Any gas that is able to capture infrared radiation and temporarily hold that energy.Different greenhouse gases absorb different
wavelengths of energy.

Gulf Stream
– Ocean surface current originating in the Caribbean Sea that moves along the
east coast of North America and then moves across the North Atlantic Ocean.

Hadalpelagic zone – Water in ocean trenches.

Hadley Cell
– Air circulation pattern where air rises at the equator and returns to the
surface at 30oN & S.This
produces low pressure and higher amounts of rainfall at the equator, and high
pressure and low precipitation at 30o.

Heat sink –
Matter or process that absorbs heat.

Heat source
– Matter or process that releases heat.

Heavy oxygen
– An isotope of oxygen with a molecular weight of 18 (18O)

Henry’s Law
– The amount of gas that can be dissolved in water is a function of temperature
and pressure.Water under high pressure
and at low temperature can hold more gas in solution than water that is warm
and under low pressure.

Incident solar radiation – Solar radiation that strikes the Earth/Atmosphere
system.This is the radiation that is
subsequently reflected, scattered, or absorbed.

Industrial Revolution – A significant change between 1750-1850 where the
mechanization of agriculture, industry, transportation, etc., caused profound
changes in the way we live, work, produce goods, etc., made possible by the
development of steam power and the use of fossil fuels.

Insolation –
A measure of solar radiation received per some unit area, e.g., Watts per meter
squared.

Intertidal zone
– The narrow zone around ocean shorelines where seafloor is exposed to the air
during low tides and covered by water during high tides.

Intertropical convergence zone (ITCZ) – Surface air flowing north and south converge
at the equator, heats up, and rises.A
perpetual band of cloud cover indicates the latitude of the ITCZ.

Isotope –
Variants of a chemical element.All
(isotopes) variants have the same number of protons but different variants
(isotopes) have different numbers of neutrons. E.g., 12C 13C
14C

Jet stream –
Narrow, fast-moving currents of air in the upper troposphere that form along
the boundaries between Hadley, Ferrel, and Polar cells.

Joule – Unit
of measurement for energy used doing work.One Joule is the same expending one Watt of energy per second.

Latent heat
– Heat that is absorbed by something without that matter changing
temperature.For example, latent heat is
released when water vapor changes into liquid water.Latent heat is absorbed as ice melts, but the
temperature of the ice does not change.

Law of conservation of matter – The amount of matter in a closed system will remain
constant.Matter can be rearranged by
location or undergo chemical change, but the total amount of matter does not
change.

Light oxygen - An isotope of oxygen with a molecular weight
of 16 (16O)

The Little Ice Age – A period of cool climate between 1600-1700 when no sunspots were
observed.Also called the Maunder
Minimum.

Mass extinction event – A time period where many species go extinct in a
short period of time.Extinction events
are often associated with rapid climate change.

Maunder Minimum
– A period of cooling climate between about 1600-1700 when no sunspots were
observed.Also called “The Little Ice
Age”.

Mesopelagic zone – This zone extends from the bottom of the epipelagic zone down to several
hundred meters to a depth where water temps cool to about 10oC.

Mesosphere –
The layer of the atmosphere that extends from about 30-53 miles in
altitude.Meteorites usually burn up as
shooting stars here.

Micrometer –
1/1000th of a millimeter. Designated by “μm”.

Mid-oceanic ridges – An interconnecting series of undersea mountain ranges, the longest
in the world, formed where tectonic forces cause seafloor spreading and new
oceanic crust is produced.

Milankovitch cycles – natural oscillations in the shape of Earth’s orbit, tilt of Earth’s
axis, and the direction the axis is pointing relative to the sun.See also eccentricity, obliquity, and
precession.

Montreal Protocol – The official name is “The Montreal Protocol on Substances that
Deplete the Ozone Layer.”This is an
international agreement to stop producing chlorine and bromine containing
substances (such as CFCs) that were discovered to deplete the stratospheric
ozone layer.The agreement was signed in
1987 and implemented in 1989.

Nanometer –
1/1,000,000th of a millimeter. Designated by “nm”.

Natural gas
– Small molecules made of carbon and hydrogen are formed when crude oil and
coal are also formed, and are gases under normal conditions.E.g., Methane, propane, butane.

Neritic zone
– The part of the ocean above the continental shelf.

Net radiation (Rnet)
– This is used to indicate the net balance of energy entering and energy
leaving a particular area of Earth’s surface.This is greatly affected by latitude.

Non-renewable energy – Any energy source that is finite or that takes such a long time to
replenish itself that it is essentially non-renewable.E.g., Fossil fuels can be replenished, but it
takes millions of years for that to happen so it is considered to be
non-renewable.

Obliquity –
Milankovitch cycle describing the oscillation of the angle of tilt of the
Earth’s axis.

Oceanic carbon sink – CO2 diffuses into seawater from the atmosphere.It or carbonates are then taken up by living
things and incorporated into their bodies.They die, and that carbon settles to the seafloor where it is covered by
sediment.

Oceanic trenches – The deepest locations in the ocean, and exist where tectonic forces
cause one plate to subduct under another plate.Volcanoes are commonly formed and earthquakes occur regularly along
trenches.

Oceanic zone
– The part of the ocean over everything except the continental shelf.

Oil (crude
oil, petroleum) – The remains of dead plankton and algae are covered by
sediment, and under intense temperature and pressure becomes a mixture of
carbon-containing molecules of different sizes that remain in a liquid state
under normal conditions.There is an
immense amount of energy stored in these compounds that is released when it
burns.

Ozone – A
molecule made of three atoms of oxygen bonded to each other.This is a harmful greenhouse gas when it is
found in the troposphere, and it protects us from UV radiation when it is in
the stratosphere.

Paleocene-Eocene Thermal Maximum (PETM) – A spike in global temperature that occurred
about 55 million years ago, as indicated by proxy data from ocean sediment
cores.

Paleoclimatology – The study of climate changes throughout Earth’s history.

Pelagic zone
– The part of the ocean where the seafloor is never uncovered by a low tide
(everything other than the intertidal zone).

Photosynthesis
– The biochemical process where energy from light is used make glucose (a
carbohydrate) from carbon dioxide and water.

Plate margins
– This is where the edges of tectonic plates meet.

Polar Cell –
Air circulation pattern where air rises at 60oN & S and returns to the
surface near the poles.This produces
low pressure and higher amounts of rainfall at 60oN and high pressure and low
precipitation at the poles.

Radiation –
This is electromagnetic energy.This is
NOT the same as radioactivity/radioactive decay.

Radiometric dating – A method for determining the absolute age of a sample by measuring
the rate of radioactive decay of radioactive atoms in it.

Rayleigh scattering – The phenomenon that produces yellows, oranges, and reds seen at dawn
and dusk, and that makes the sky appear blue the rest of the time.Most Rayleigh scattering is done by molecules
in the atmosphere, and blue light scatters more than other colors.This is what gives the sky it’s blue
color.At dawn and dusk light travels
through more light to reach the surface, scattering all blue light and leaving
only longer wavelength light – reds, oranges.Air pollution can accentuate Rayleigh scattering since there are more
particles in the air and light scatters more than otherwise.

Ridge (jet
stream) - In the northern hemisphere where a jet stream swoops toward the
north, and at the same time rises to a higher altitude.A high-pressure cell forms at lower altitudes
as air from a jet stream descends from a ridge toward a trough.

Relative reference frame (Coriolis Effect) – The observer is on the surface of
the planet, and is thus changing position as the Earth rotates.From this frame of reference the apparent
path of an object deflects to the right in the northern hemisphere and to the left
in the southern hemisphere.

Renewable energy – Energy that comes from natural sources that can be replenished in a
short period of time by natural processes, e.g., wood, wind, hydroelectric,
solar panels, tides, biofuels, etc.

Rotational motion – The amount of spin a body experiences as the Earth rotates.A body experiences 100% rotational motion
when it is at one of Earth’s poles, and 0% rotational motion when it is on the
equator.

Salinity –
The salt content of water.

Scattering
(of light) – The redirection of a ray of solar energy resulting from contact
with aerosols.

Second law of thermodynamics – The amount of energy able to do work decreases
whenever energy is transformed.Every
time energy is transformed entropy is produced and released as waste heat.

Sediment core
– A cylindrical a sample of the sediment removed from the bottom of the ocean
or a lake by using a plug or a drill.

Solar faculae
– Brighter, hotter areas on the surface of the sun that form when sunspots are
also present.

Specific heat –
The amount of heat needed to change a substance’s temperature.E.g., A substance with a high specific heat
absorbs lots of heat before its temperature will change very much.Water has the highest specific heat of any common
substance.

Speleotherm
– Stalactites, stalagmites, and other formations are formed when ions and other
materials are dissolved by water as it percolates through rock layers, and that
material is deposited when that water drips into a cave.

Stalagmite –
A speleotherm that rises from the floor of a cave/cavern.

Stratosphere
– The layer of the atmosphere that extends from 7-30 miles above the Earth’s
surface.This is where the ozone layer
exists that protects us from harmful UV radiation.

Subduction/Subducted – A tectonic process where one crust plate is pushed underneath
another crust plate.

Thermohaline circulation – The circulation of ocean waters driven by a
combination of temperature and salinity factors that causes seawater to become
dense enough to sink.Major centers of
thermohaline circulation are the North Atlantic and the waters surrounding
Antarctica.

Thermosphere
– The layer of the atmosphere that extends from 53-90 miles in altitude.This is the top layer of Earth’s atmosphere.

Translational motion - The degree to which a body changes position as the Earth
rotates.A body experiences 0% motion
when it is at one of Earth’s poles (it spins, but doesn’t change position), and
100% rotational motion when it is on the equator (it moves, but doesn’t spin at
all).

Tree ring –
Trees that experience seasonal growth produce one wide ring and one narrow ring
of wood.Together these rings represent
one year’s worth of growth.A tree’s age
and annual growing conditions can be inferred from these rings.

Tropic of Cancer – A line of latitude 23.5oN, the farthest north you can go
and have the sun directly overhead for only one day a year (on the summer
solstice).

Tropic of Capricorn – A line of latitude 23.5oS, the farthest south you can go
and have the sun directly overhead for only one day a year (on the winter
solstice).

Troposphere
– The layer of the atmosphere closest to the Earth’s surface, extending to an
altitude of 3-12 miles.This is where
the vast majority of Earth’s weather events take place.

Trough (jet
stream) – In the northern hemisphere where a jet stream dips toward the south,
and at the same time dips to a lower altitude.A low pressure cell forms in lower altitudes as a jet stream rises from
a trough toward a ridge.

Upwelling –
When deep, cool, nutrient-rich water is pulled up to the surface, usually by
Ekman transport or offshore winds.